California Auto Insurance: Radar Detector Law & Legalities

By Insurance.com Posted : 02/19/2007

Are "radar busters" legal? The answer in California depends on the type of technology you use and how you use it.

Avoiding speeding tickets is big business in the United States, thanks to developments in technology since the "Fuzzbusters" of the 1970s. Drivers today can choose from a host of radar detectors, laser detectors, scanners, jammers and stealth coatings designed to elude law enforcement officials. Recent estimates suggest that over 10 percent of all drivers employ some sort of "radar-busting" technology on our nation's highways.

Before you decide to use this type of equipment, you should know the laws governing them, as well as how these devices work.

Radar & Laser JammersUnder California law, the use of radar and laser jammers is illegal. It is also a felony under federal law to jam or attempt to jam police radar signals. Many states criminalize the mere possession of a radar jammer, so it is best to avoid such products altogether.

Police ScannersUnder California law, it is illegal to use a police scanner in the commission of a crime. All other uses are permitted (See: http://www.leginfo.ca.gov).

Stealth CoatingsTo date, neither California nor any other state has banned the use of stealth coatings to impair the ability of police LIDAR laser guns ("Light Detection and Ranging") to obtain an accurate speed reading of a vehicle. Stealth coatings first gained notoriety due to their defense applications (such as with the Stealth Bomber). Their efficacy on the roadways remains to be seen, although some testers claim that stealth coatings can reduce laser gun sensitivity by up to 50 percent (see http://www.radarbusters.com/2003lasercoatingsarticle.cfm).

Radar & Lidar DetectorsUnder federal law, the use of radar and LIDAR detectors is illegal in all commercial vehicles over 10,000 pounds. For all other purposes, radar and LIDAR detectors are legal in California.

In light of the obvious conflict between speeding laws and radar detector use, law enforcement officials, safety advocates, and insurance companies continue to lobby to legislators nationwide to ban the use of radar and laser detectors altogether. Thus far, they have only been successful in banning radar detector use in Virginia, Washington D.C., and on U.S. military bases.

Some speculate that one of the reasons that legislators have been loathe to ban consumer use of radar detectors is that such bans could expose the inaccuracy of radar and laser-based speed detection systems. Independent studies have shown that radar and laser guns are susceptible to technical and operator error, leading some radar detection advocates to claim that over 25 percent of all radar-based speeding tickets are generated in error (see http://www.radarbusters.com/2003lasercoatingsarticle.cfm ). Some of the more common reasons for errors include:

Radio Frequency Interference (RFI) from sources such as radios, garage door openers, and police radar.

Cosine errors generated by an inappropriate angle of the gun to the target.

Mechanical errors caused by guns overheating or being out of alignment.

Regardless of the accuracy of speed detection systems or the legality of radar detectors, one fact remains crystal clear in California -- speeding is against the law. Accordingly, the best advice is for California drivers to rely on their common sense, rather than technology, when assessing the proper speed for the prevailing road conditions. For more information on safe driving in California, please visit http://www.dmv.ca.gov. If you're interested in learning more about radar detectors, please visit the RadarBusters.com Buyer's Guide.